Electromagnetic signal hooter



March 14, 1944. zElNlNGER 2,344,119

ELECTROMAGNETIC SIGNAL HOOTER Filed Nov. 23, 1940 /n venfor Affo/neyPatented Mar. 14, 1944 OFFICE ELECTROMAGNETIC SIGNAL HOOTER GustavZeininger, Oberesslingen, vested in the Alien Property ApplicationNovember 23 In Germany No 2 Claims.

This invention relates to electromagnetic signal horns or hooters of thetype used in motor vehicles.

It is an important object of the present invention to provide means indevices of the type referred to for ensuring an eflicient spark reducingor quenching at the contacts of the interrupter.

Another object of the invention is to provide means for preventing thedistortion of the sound of the horn produced in the conventional hornsas a result of a too high operating voltage, which of course is due tothe variations of the battery voltage arising from the differentcharging conditions of the same.

With these objects in view, I provide on the electromagnet an auxiliarywinding which is connected across the contacts of the interrupter andconsists of a smaller gauge wire than the main winding, the auxiliarywinding being arranged so as to produce a unidirectional magnetisingeffect with that of the main winding.

The invention will be better understood by reference to the followingdetailed description in connection with the accompanying drawing,showing by way of example and purely schematically a diagram ofconnection of a signal horn device having the invention applied thereto.

It will be seen from the drawing that the horn comprises a diaphragm Iconnected to, and oscillated by, an armature 2 forming part of anelectromagnet 3 including a main winding 4 and an auxiliary winding 5being inductively intercoupled. The diaphragm at its rim is held betweenrings l4. The auxiliary winding 5 consists of a thinner wire than themain winding 4, for instance, of a wire having half the diameter of themain winding 4, and is arranged to cause a magnetisation in thedirection of arrow I2, 1. e., in the same direction as that of the maincoil 4 which is indicated by arrow 13, when both coils are energized.

The armature 2 actuates a contact spring 6 of an interrupter whosecontacts 1, l are connected in series with the main coil 4, whilst theauxiliary winding 5 is connected in parallel with the interruptercontacts 1, 1, whereby the potential produced at the terminals of themain coil 4 due to selfinduction is permitted to equalize. Owing to thespark diminishing or extinguishing effect thereby attained the condenserwhich usually is Germany; Custodian 1940, Serial No. 366,912 vember 21,1939 connected across the interrupter contacts may be dispensed with.

Moreover, it has been found that by provision of the auxiliary coil 5 apure sound is produced even if the operating voltage exceeds the nominalvoltage of the horn. Thus, the purity of the tone produced by the hornbecomes independent of the voltage variations of the source of current 9of the horn. The current consumption of the auxiliary coil 5 is verysmall.

A push button 8 serves for switching in the horn. The battery 9 for thehorn may be charged from a generator I I, through an automatic switchIll.

The method and apparatus of the present invention have been described indetail with reference to a specific embodiment. It is to be understood,however, that the invention is not limited by such specific referencebut is broader in scope and capable of other embodiments than thatspecifically described and illustrated in the drawing.

I claim:

1. An electromagnetic horn comprising an electromagnet, a soundproducing diaphragm, an armature for operating said diaphragm and aninterrupter, actuated by said armature, for said electromagnet, saidelectromagnet including a main winding and an auxiliary winding, bothcontrolled by said interrupter during the operation of said horn, saidwindings being inductively intercoupled and said auxiliary winding beingconnected across the interrupter contacts, to energize the electromagnetin the same direction as the main winding.

2. An electromagnetic signal horn comprising an electromagnet, a soundproducing diaphragm, an armature for operating said diaphragm and aninterrupter, actuated by said armature, for said electromagnet, saidelectromagnet including a main winding and an auxiliary winding, bothcontrolled by said interrupter during the operation of said horn, saidwindings being inductively intercoupled and said auxiliary windingc0hsisting of thinner wire than that of the main Winding and beingconnected across the interrupter contacts, to energize the electromagnetin the same direction as the main winding.

GUSTAV ZEININ GER.

